Introduction:
Groin pain is viewed as a difficult entity. There are multiple diagnostic terms, which can lead to confusion. Groin pain makes up 5% of all athletic injuries. It is common in direction change sports such as soccer and AFL, making up 25% of injuries in soccer. Groin pain should be considered in 2 main diagnostic groups, described as ‘pubalgic’ and ‘non-pubalgic’. The pubalgic group includes the entities of adductor tendinopathy, osteitis pubis, posterior inguinal wall weakness (or ‘sports hernia’) and illiopsoas tendinopathy. In 30-40% of cases there may be more than one of these entities causing pain concurrently. Non-pubalgic pain is dominated by the hip joint where diagnoses such as osteoarthritis, stress fracture, avascular necrosis and femoroacetabular impingement need to be considered.
Aetiology:
The aetiology of ‘pubalgic’ groin pain is multifactorial. It may come as a consequence of acute injury, or more commonly as an overload of the soft tissue or bony structures around the pelvis. A combination of restricted hip motion and weakness or inflexibility of the adductor and lower abdominal muscles causes increased shear forces through the pelvis with direction change activity. Subsequent overload may lead to pain from the adductor, illiopsoas or conjoint tendons, or the pubic symphysis. Pain then causes further soft tissue dysfunction, causing a further deterioration of symptoms.
Diagnosis:
Historically the pubalgic causes of groin pain will tend to be worsened by running with direction change, and are more common in young men. As the problem in osteitis pubis is bony, the patient usually complains of a deep aching pain during and after activity. Lower abdominal problems may be aggravated by coughing or sneezing. Older patients are more likely to have degenerative hip disease.
In adductor tendinopathy the patient will have tenderness over the bone/tendon interface or pain on resisted hip adduction. Osteitis pubis may be diagnosed by a positive ‘squeeze test’, causing either pain or adduction weakness. Lower abdominal problems may be provoked by abdominal testing, such as resisted sit-ups. Hip joint problems may be reflected by loss of hip motion, especially in rotation, flexion and abduction. The ‘hip quadrant’ or FADIR test is sensitive for early osteoarthritis or an acetabular labral tear.
Investigation
A plain x-ray is essential to demonstrate hip arthritis or other pathology such as a stress fracture. It will also show erosions around the pubic symphysis in osteitis pubis. MRI is helpful to assess the spectrum of pathology, including adductor or illiopsoas tendinopathy and may demonstrate bone marrow oedema or degenerative changes in osteitis pubis, or hip joint pathology such as early osteoarthritis or acetabular labral tears. Sports hernias are diagnosed most accurately by ultrasound performed by an experienced radiologist.
Treatment:
The treatment for all causes of pubalgic groin pain is similar and is initially non-surgical. Generally it is favorable, although may run a protracted time course. It involves unloading the groin from impact and direction change sports. Physiotherapy is essential to release the soft tissues of the adductors, hip flexors and gluteals and to improve hip joint mobility. A program of strengthening for core musculature, gluteals and adductors is also required. In one trial for adductor tendinopathy an 80% improvement occurred in patients treated with an exercise program compared to 15% of those treated with passive therapy alone (1). Injections of either corticosteroids or other agents may be an adjunct to the physical program in adductor tendinopathy. A return to training program is guided by improvement in clinical symptoms, but may take many months, especially in osteitis pubis. If symptoms are not settling then surgery in the form of an adductor tendon release or a hernia repair may be indicated.
Key Points:
- Groin pain usually occurs in sports that require running and direction change, such as soccer and AFL
- A key differentiation is between ‘pubalgic’ and ‘non-pubalgic’ pain.
- Common causes of pubalgic pain are adductor tendinopathy, osteitis pubis or ‘sports hernia’
- The most common source of non-pubalgic pain, and of groin pain in general, is the hip joint
- Pubalgic groin pain requires a comprehensive rehabilitation program. The time course may be lengthy, and surgery is occasionally required.
References:
- Hölmich P, Uhrskov P, Ulniths L, et al. Effectiveness of active physical training as a treatment for long-standing adductor-related groin pain in athletes: randomised trial. Lancet 1999; 353: 439-443